1. Field of the Invention
The present invention is directed to an x-ray scanner having an x-radiator which generates a fan-shaped x-ray beam at one side of a conveyor means, and a line of individual detectors at the other side of the conveyor means with goods to be inspected being moved through the beam by the conveyor means.
2. Description of the Prior Art
Such scanners are known which include electronics for the acquisition and processing of the detector signals a following viewing means. The electronics includes at least one image storage which having a respective memory row per each individual detector, and a comparator for the recognition of faulty detector signals by means of which the roll-in of data into the image memory is controllable, such that the transfer of the information into the memory row allocated to the detector is inhibited given a faulty detector signal.
X-ray scanners of this type are used, for example, for inspecting luggage. Each of the detectors can be composed of a scintillator for converting x-radiation into visible light which is then converted into an electrical current by a photodiode. For processing the measured values in parallel form, the measured values are converted into a serial sequence of analog measured values via electronic switches (multiplexers), are digitized and are written into a digital image memory such that a running image arises upon display of the storage contents on a video monitor via a digital-to-analog converter. Given a horizontally running image, data are written into the image memory in columns. Every detector then generates a line of the video picture.
An x-ray scanner of this type is known wherein the detector line is bent at a right angle and extends over two sides of the examination space. The location-dependent distortion thereby occurring is eliminated in accord with the teachings of E-A-No. 0 100 562 using an allocator unit which, on the basis of electronically controlled omission of detector channels, equalizes the non-linear scaling function such that the imaging scale corresponds to that of an ideally linear or circular arc-shaped line. In this known x-ray scanner, the perception has been exploited that individual, missing detector channels within the detector row do not lead to a noticeable deterioration of the generated video picture. Permanently prescribed detector channels are thereby omitted.
An individual detector can fail in an x-ray scanner of this type. If the down detector is adjacent to the detector omitted in accord with the program, this would potentially generate a disturbance visible in the pictorial display if the gradient of the gray scale value, i.e., of the signal amplitude, is adequately high at this location.